Remotely operated vehicles for picking up storage bins from a storage system are known. A detailed description of a relevant prior art storage system is presented in WO 98/49075, and details of a prior art vehicle being suitable for such a storage system is disclosed in detail in Norwegian patent NO317366. Such prior art storage systems comprise a three dimensional storage grid containing storage bins that are stacked on top of each other up to a certain height. The storage grid is normally constructed as aluminium columns interconnected by top rails, onto which a plurality of remotely operated vehicles, or robots, are arranged to move laterally. Each vehicle is equipped with a vehicle lift assembly for picking up, carrying, and placing bins that are stored in the storage grid, and a rechargeable battery in order to supply electrical power to a vehicle incorporated motor. The vehicle typically communicates with a control system via a wireless link and is recharged at a charging station when needed, typically at night.
In the known remotely operated vehicles/robots, the lifting assemblies used for picking up, carrying, and placing storage bins commonly comprise a lift frame connected to the vehicle by two pairs of wirelines/bands. Each pair of wirelines/bands is spooled onto a separate rotatable lifting shaft. The prior art lifting assemblies require highly accurate synchronization of the separate rotatable lifting shafts to avoid skewed lifting of the storage bin, and complex power transfer means to allow one drive unit to run both lifting shafts.
It is thus an object of the present invention to provide a vehicle/robot having an improved lift assembly, wherein at least some of the disadvantages of the prior art is alleviated.